System and method for managing an auxiliary spittoon in a printer

Abstract

A system and method for substantially optimizing print quality or throughput based upon user preferences through use of a left spittoon to perform servicing operations on the printhead of a printer. By virtue of the fact that print quality is inversely proportional to throughput, sacrificing one aspect yields an improvement in the other aspect. When a certain printmode is selected, e.g., draft, print, or the like, the throughput associated with printing according to the selected printmode may vary. Accordingly, a user may select to improve either the print quality, the throughput, or a combination thereof through implementation of the auxiliary spittoon to perform servicing operations on the printhead at various times during a printing operation.

What is claimed is:  
     
       1. A method for operating a printer having a main spittoon, an auxiliary spittoon, and printhead, said printhead being operable to perform a uni-directional or bi-directional printing pass, said method comprising: 
       receiving a selected printmode;  
       determining a decap time in response to said received printmode;  
       estimating a nominal time to complete a uni-directional sweep and a bi-directional sweep;  
       determining a last time said printhead was refreshed; and  
       performing a servicing operation on said printhead in response to said last time said printhead was refreshed exceeding a predetermined value.  
     
     
       2. The method according to  claim 1 , wherein said step of determining a last time said printhead was refreshed comprises: 
       determining which nozzles of said printhead were utilized in firing ink onto each cell of a prior printing pass;  
       determining a total amount of ink fired into each said cell by said utilized nozzles;  
       approximating an amount of ink fired by each of said utilized nozzles based on said total amount of ink fired into each cell;  
       detecting a time and cell in which the number of utilized nozzles is equal to or exceeds a predetermined threshold percentage of total nozzles in said printhead and in which the amount of ink fired into said cell is equal to or exceeds a predetermined threshold amount of ink; and  
       setting said last time said printhead was refreshed in accordance with said detected time and cell.  
     
     
       3. The method according to  claim 1 , wherein said step of estimating a nominal time to complete a uni-directional sweep and a bi-directional sweep comprises determining the width of an upcoming plot. 
     
     
       4. The method according to  claim 1 , further comprising: 
       determining whether said printmode is uni-directional; and  
       determining whether a uni-directional sweep time exceeds said decap time in response to said printmode being uni-directional.  
     
     
       5. The method according to  claim 4 , further comprising: 
       determining whether a sum of a current time and the uni-directional sweep time minus a last time a spit on the fly was performed is greater than or equal to said decap time;  
       performing a spitting operation of said printhead said main spittoon in response to said sum of said current time and said uni-directional sweep time minus a last time a spit on the fly was performed being greater than or equal to said decap time; and  
       performing a uni-directional printing pass with said printhead.  
     
     
       6. The method according to  claim 4 , further comprising: 
       performing a spitting operation of said printhead in said main spittoon in response to said uni-directional sweep time exceeding said decap time; and  
       performing a uni-directional printing pass with said printhead.  
     
     
       7. The method according to  claim 1 , further comprising: 
       determining whether said printing pass is a left to right sweep in response to said printmode being bi-directional.  
     
     
       8. The method according to  claim 7 , further comprising: 
       determining whether a single sweep time exceeds said decap time in response to said printing pass being a left to right sweep.  
     
     
       9. The method according to  claim 8 , further comprising: 
       determining whether a sum of a current time and the uni-directional sweep time minus a last time a spit on the fly was performed is greater than or equal to said decap time.  
     
     
       10. The method according to  claim 9 , further comprising: 
       determining whether a pass width of said printing pass is greater than or equal to a predetermined minimum pass width threshold in response to said sum of said current time and the uni-directional sweep time minus said last time a spit on the fly was performed being greater than or equal to said decap time;  
       performing a spitting operation in said auxiliary spittoon in response to said pass width of said printing pass being greater than or equal to said predetermined minimum pass width threshold; and  
       performing a bi-directional printing pass with said printhead.  
     
     
       11. The method according to  claim 7 , further, comprising: 
       determining whether a bi-directional sweep time exceeds said decap time in response to said printing pass being a right to left sweep.  
     
     
       12. The method according to  claim 1 , further comprising: 
       performing a spitting operation of said printhead in said main spittoon in response to said bi-directional sweep time exceeding said decap time; and  
       performing a bi-directional printing pass with said printhead.  
     
     
       13. The method according to  claim 11 , further comprising: 
       determining whether a sum of a current time and the bi-directional sweep time minus a last time a spit on the fly was performed is greater than or equal to said decap time in response to said bi-directional sweep time being less than said decap time;  
       performing a spitting operation of said printhead in said main spittoon in response to said bi-directional sweep time minus a last time a spit on the fly was performed being greater than or equal to said decap time; and  
       performing a bi-directional printing pass with said printhead.  
     
     
       14. The method according to  claim 1 , further comprising: 
       performing a control spitting operation in one of said main spittoon and said auxiliary spittoon at a predetermined time during a printing operation, wherein said control spitting operation is performed in the main spittoon or the auxiliary spittoon based upon the spittoon the printhead is nearer at the predetermined time.  
     
     
       15. An apparatus for operating a printer having a main spittoon, an auxiliary spittoon, and a printhead, said printhead being operable to perform a uni-directional or bi-directional printing pass, said apparatus comprising: 
       a controller configured to receive a selected printmode and determine a decap time in response to said received printmode;  
       said controller further configured to estimate a nominal time to complete a uni-directional sweep and a bi-directional sweep; and  
       said controller further configured to determine a last time said printhead was refreshed.  
     
     
       16. The apparatus according to  claim 15 , wherein said controller is further configured to determine whether said printing pass is a left to right sweep in response to said printmode being bi-directional. 
     
     
       17. The apparatus according to  claim 16 , wherein said controller is further configured to determine whether a uni-directional sweep time exceeds said decap time in response to said printing pass being a left to right sweep. 
     
     
       18. The apparatus according to  claim 17 , wherein said controller is further configured to determine whether a sum of a current time and the uni-directional sweep time minus a last time a spit on the fly was performed is greater than or equal to said decap time. 
     
     
       19. The apparatus according to  claim 17 , wherein said controller is further configured to determine whether a pass width of said printing pass is greater than or equal to a predetermined minimum pass width threshold in response to said sum of said current time and the uni-directional sweep time minus said last time a spit on the fly was performed being greater than or equal to said decap time. 
     
     
       20. The apparatus according to  claim 19 , wherein said controller is further configured to control the printhead to perform a spitting operation in said auxiliary spittoon in response to said pass width of said printing pass being greater than or equaling said minimum pass width threshold and to perform a bi-directional printing pass with said printhead. 
     
     
       21. A method for managing an auxiliary spittoon in a printer having a main spittoon and a printhead, said printhead being operable to perform a uni-directional or bi-directional printing pass, said method comprising: 
       receiving a selected printmode;  
       determining a decap time in response to said received printmode;  
       estimating a nominal time to complete a uni-directional sweep and a bi-directional sweep;  
       determining a last time said printhead was refreshed;  
       determining whether said printing pass is a left to right sweep in response to said printmode being bi-directional;  
       determining whether a uni-directional sweep time exceeds said decap time in response to said printing pass being a left to right sweep;  
       performing a spitting operation of said printhead in said auxiliary spittoon in response to a sum of a current time and the uni-directional sweep time minus a last time a spit on the fly was performed being greater than or equal to said decap time; and  
       performing a bi-directional printing pass with said printhead.  
     
     
       22. The method according to  claim 21 , wherein said step of determining a last time said printhead was refreshed comprises: 
       determining which nozzles of said printhead were utilized in firing ink onto each cell of a prior printing pass;  
       determining a total amount of ink fired into each said cell by said utilized nozzles;  
       approximating an amount of ink fired by each of said utilized nozzles based on said total amount of ink fired into each cell;  
       detecting a time and cell in which the number of utilized nozzles is equal to or exceeds a predetermined threshold percentage of total nozzles in said printhead and in which the amount of ink fired into said cell is equal to or exceeds a predetermined threshold amount of ink; and  
       setting said last time said printhead was refreshed in accordance with said detected time and cell.  
     
     
       23. The method according to  claim 21 , further comprising: 
       determining whether a pass width of said printing pass is greater than or equal to a predetermined minimum pass width threshold prior to performing said spitting operation.  
     
     
       24. The method according to  claim 23 , further comprising: 
       performing said spitting operation of said printhead in said auxiliary spittoon in response to said pass width of said printing pass being greater than or equaling said minimum pass width threshold; and  
       omitting said spitting operation in response to said pass width of said printing pass being less than said minimum pass width threshold.  
     
     
       25. The method according to  claim 21 , further comprising: 
       performing a control spitting operation in one of said main spittoon and said auxiliary spittoon at a predetermined time during a printing operation, wherein said control spitting operation is performed in the main spittoon or the auxiliary spittoon based upon the spittoon the printhead is nearer at the predetermined time.  
     
     
       26. A computer readable storage medium on which is embedded one or more computer programs, said one or more computer programs implementing a method for operating a printer having a main spittoon, an auxiliary spittoon, and a printhead, said printhead being operable to perform a uni-directional or bi-directional printing pass, said one or more computer programs comprising a set of instructions for: 
       receiving a selected printmode;  
       determining a decap time in response to said received printmode;  
       estimating a nominal time to complete a uni-directional sweep and a bi-directional sweep;  
       determining a last time said printhead was refreshed;  
       determining whether said printing pass is a left to right sweep in response to said printmode being bi-directional;  
       determining whether a uni-directional sweep time exceeds said decap time in response to said printing pass being a left to right sweep;  
       performing a spitting operation of said printhead in said auxiliary spittoon in response to a sum of a current time and the uni-directional sweep time minus a last time a spit on the fly was performed is greater than or equal to said decap time; and  
       performing a bi-directional printing pass with said printhead.  
     
     
       27. The computer readable storage medium according to  claim 26 , said one or more computer programs further comprising a set of instructions for: 
       determining which nozzles of said printhead were utilized in firing ink onto each cell of a prior printing pass;  
       determining a total amount of ink fired into each said cell by said utilized nozzles;  
       approximating an amount of ink fired by each of said utilized nozzles based on said total amount of ink fired into each cell;  
       detecting a time and cell in which the number of utilized nozzles is equal to or exceeds a predetermined threshold percentage of total nozzles in said printhead and in which the amount of ink fired into said cell is equal to or exceeds a predetermined threshold amount of ink; and  
       setting said last time said printhead was refreshed in accordance with said detected time and cell.  
     
     
       28. The computer readable storage medium according to  claim 26 , said one or more computer programs further comprising a set of instructions for: 
       determining whether a pass width of said printing pass is greater than or equal to a predetermined minimum pass width threshold prior to performing said spitting operation.  
     
     
       29. The computer readable storage medium according to  claim 28 , said one or more computer programs further comprising a set of instructions for: 
       performing said spitting operation of said printhead in said auxiliary spittoon in response to said pass width of said printing pass being greater than or equaling said minimum pass width threshold; and  
       omitting said spitting operation in response to said pass width of said printing pass being less than said minimum pass width threshold.  
     
     
       30. The computer readable storage medium according to  claim 26 , said one or more computer programs further comprising a set of instructions for: 
       performing a control spitting operation in one of said main spittoon and said auxiliary spittoon at a predetermined time during a printing operation, wherein said control spitting operation is performed in the main spittoon or the auxiliary spittoon based upon the spittoon the printhead is nearer at the predetermined time.